1. Field of the Invention
The present invention generally relates to imaging and, more particularly, to an apparatus including an image reading unit, such as a scanner, a printer, a facsimile machine, a copying machine, and a multifunction peripheral (MFP).
2. Description of the Related Art
Japanese Patent Application Laid-Open No. 2009-88759 discusses an MFP which includes an image reading unit. The device includes a reading unit, which is configured to read an image of a document set on a reading surface, and a pressing plate, which can open on the reading surface. On an upper surface of the pressing plate, an operation unit, which includes a plurality of input keys, and a display device, such as a liquid crystal display (LCD) panel, are provided.
U.S. Patent Application Publication No. 2009/0033636 A1 discusses a capacitive touch panel input device. The capacitive touch panel input device includes a substrate and a spacer. A plurality of sensor electrodes is implemented on the capacitive touch panel input device. The spacer is set on each sensor electrode.
The spacer includes a first block provided on the electrode and a second block provided within the first block. The conductivity of the second block is lower than that of the first block. Accordingly, the above-described conventional method prevents an error input by hardly receiving the affect from adjacent sensor electrodes.
Another conventional method discussed in the Japanese Patent Application Laid-Open No. 2009-88759 includes an operation unit that has a structure of a mechanical-contact key, such as a tactile switch. However, in terms of lower costs and appropriate component arrangement and design, the operation unit can be replaced with the capacitive input device, such as the one discussed in the U.S. Patent Application Publication No. 2009/0033636 A1.
In the apparatus discussed in the U.S. Patent Application Publication No. 2009/0033636 A1, it is required to divide the spacer into a multiple of minute blocks and to arrange them at precise locations. Accordingly, the configuration of a switch may become too complicated to easily manufacture the stitch. Furthermore, it may become difficult to reduce the costs of manufacture thereof.
In addition, in the apparatus discussed in the U.S. Patent Application Publication No. 2009/0033636 A1, if air enters the space between the sensor electrode on the substrate and the spacer during assembly and if a partial air gap arises, the capacitance may not be detected at a high accuracy. Accordingly, extreme care is necessary when assembling the apparatus discussed in the U.S. Patent Application Publication No. 2009/0033636 A1.